Two table common key and relationship issue...

FreemanZ ,

Can't do it because Table 1 is the main table which has almost all the data and dates except few of them shown above.

So I have to put Table 1 column first.

I have changed a bit in question, please check again.

Hi ddpl ,

I created a sample pbix file(see attachment) for you, please check whether that is what you want. You can create two measures as below:

Count(Table 1) = 
VAR _selclientid =
    SELECTEDVALUE ( 'Table1'[Client ID] )
VAR _count =
    CALCULATE (
        COUNT ( 'Table1'[Date] ),
        FILTER ( ALLSELECTED ( 'Table1' ), 'Table1'[Client ID] = _selclientid )
    )
RETURN
    _count

Count(Table 2) = 
VAR _selclientid =
    SELECTEDVALUE ( 'Table1'[Client ID] )
VAR _count =
    CALCULATE (
        COUNT ( 'Table2'[Date] ),
        FILTER ( ALLSELECTED ( 'Table2' ), 'Table2'[Client ID] = _selclientid )
    )
RETURN
    _count

Best Regards